The influence of Ti-Si-Mg-AI wire on microstructure and mechanical properties of SiCp/A1 metal matrix composite joints produced by plasma arc in-situ weld-alloying was investigated. Argon-nitrogen mixture was used as ...The influence of Ti-Si-Mg-AI wire on microstructure and mechanical properties of SiCp/A1 metal matrix composite joints produced by plasma arc in-situ weld-alloying was investigated. Argon-nitrogen mixture was used as plasma gas and Ti-Si-Mg-A1 flux-cored wires as filled composites. Weldments were submitted to tensile test. Meanwhile, the macro morphology and microstructure of the joints were examined. The result shows that the formation ofneedie-like harmful phase A14C3 is effectively inhibited and the wettability of molten pool is improved by adding Ti-Si-Mg-A1 flux-cored wires. With 15Ti-5Si-5Mg-A1 flux-cored wire as filled composite, the maximum tensile strength of the welded joint is 267 MPa, which is up to 83% that of the matrix composites under annealed condition.展开更多
DS18 B2 0是 DAL L AS公司生产的单线数字温度传感器 ,他具有独特的单线总线接口方式。文章详细的介绍了单线数字温度传感器 DS18B2 0的测量原理、特性以及在温度测量中的硬件和软件设计 ,具有接口简单、精度高、抗干扰能力强、工作稳...DS18 B2 0是 DAL L AS公司生产的单线数字温度传感器 ,他具有独特的单线总线接口方式。文章详细的介绍了单线数字温度传感器 DS18B2 0的测量原理、特性以及在温度测量中的硬件和软件设计 ,具有接口简单、精度高、抗干扰能力强、工作稳定可靠等特点。展开更多
Considering special working conditions of under ground coal mines,traditional IC cards,magnetic cards or radio frequency cards do not work well in entrance guard and work attendance check system because of inconvenien...Considering special working conditions of under ground coal mines,traditional IC cards,magnetic cards or radio frequency cards do not work well in entrance guard and work attendance check system because of inconvenient carry,damaged easily and unsuitable in severe surroundings.So an access and attendance system for mine which is more firmly,durable and good performance is designed using new intelligent information carrier-iButton(Information Button).For iButton has a stainless steel shell,which make it has the advantages of anti-strike,antirust,anti-magnetism and anti-folded,the reliability of the system is enhanced greatly.展开更多
IEEE802.15.4 is the communication protocol meeting the requirements of short distance and low transmission rate, and achieving the objective of low power. The technique is an emerging wireless communication standard. ...IEEE802.15.4 is the communication protocol meeting the requirements of short distance and low transmission rate, and achieving the objective of low power. The technique is an emerging wireless communication standard. It is a two-way wireless communication technology with short distance, low complexity, low power consumption and low data transmission rate and low cost. The paper analyzes the features, framework, performance indicators and overall hardware platform structure of JN5121 chip which is used in JENNIC Corporation. And the paper researches the characteristics of actual oroducts for project development.展开更多
Since Bi2Sr2Ca1Cu2O8＋x（Bi2212） wires are subject to mechanical loadings, degradation of critical current will occur. The effect of compressive loadings on the critical current of Bi2212 wire is studied by consideri...Since Bi2Sr2Ca1Cu2O8＋x（Bi2212） wires are subject to mechanical loadings, degradation of critical current will occur. The effect of compressive loadings on the critical current of Bi2212 wire is studied by considering micro-buckling of filament. A Bi2212 wire is regarded as a unidirectional filament-reinforced composite in the theoretical analysis. By considering the influence of inclusion, the micro-buckling wavelength can be derived by using a two-dimensional model. Based on the experimental results, the critical current is fitted as a function of buckling wavelength. It is found that the decrease of the critical current is directly proportional to the reciprocal of square of the buckling wavelength. Change of micro-buckling wavelength with material parameters is discussed. A critical strain in the wire with a filament bridge is analyzed using the finite element method.展开更多
基金Project (09003) supported by the Open-Fund Research of State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,ChinaProject (JD0805) supported by the Science and Technology Innovation Team,Jiangsu University,China
文摘The influence of Ti-Si-Mg-AI wire on microstructure and mechanical properties of SiCp/A1 metal matrix composite joints produced by plasma arc in-situ weld-alloying was investigated. Argon-nitrogen mixture was used as plasma gas and Ti-Si-Mg-A1 flux-cored wires as filled composites. Weldments were submitted to tensile test. Meanwhile, the macro morphology and microstructure of the joints were examined. The result shows that the formation ofneedie-like harmful phase A14C3 is effectively inhibited and the wettability of molten pool is improved by adding Ti-Si-Mg-A1 flux-cored wires. With 15Ti-5Si-5Mg-A1 flux-cored wire as filled composite, the maximum tensile strength of the welded joint is 267 MPa, which is up to 83% that of the matrix composites under annealed condition.
基金supported by the Natural Science Foundation of Shandong Province(ZR2009GQ012)Science and Technology Development Plan of China National Coal Association(10-067)
文摘Considering special working conditions of under ground coal mines,traditional IC cards,magnetic cards or radio frequency cards do not work well in entrance guard and work attendance check system because of inconvenient carry,damaged easily and unsuitable in severe surroundings.So an access and attendance system for mine which is more firmly,durable and good performance is designed using new intelligent information carrier-iButton(Information Button).For iButton has a stainless steel shell,which make it has the advantages of anti-strike,antirust,anti-magnetism and anti-folded,the reliability of the system is enhanced greatly.
文摘IEEE802.15.4 is the communication protocol meeting the requirements of short distance and low transmission rate, and achieving the objective of low power. The technique is an emerging wireless communication standard. It is a two-way wireless communication technology with short distance, low complexity, low power consumption and low data transmission rate and low cost. The paper analyzes the features, framework, performance indicators and overall hardware platform structure of JN5121 chip which is used in JENNIC Corporation. And the paper researches the characteristics of actual oroducts for project development.
基金Project supported by the National Natural Science Foundation of China(Nos.11327802,11472120,and 11421062)the National Key Project of Magneto-Constrained Fusion Energy Development Program(No.2013GB110002)the Fundamental Research Funds for the Central Universities(No.lzujbky-2017-k18)
文摘Since Bi2Sr2Ca1Cu2O8＋x（Bi2212） wires are subject to mechanical loadings, degradation of critical current will occur. The effect of compressive loadings on the critical current of Bi2212 wire is studied by considering micro-buckling of filament. A Bi2212 wire is regarded as a unidirectional filament-reinforced composite in the theoretical analysis. By considering the influence of inclusion, the micro-buckling wavelength can be derived by using a two-dimensional model. Based on the experimental results, the critical current is fitted as a function of buckling wavelength. It is found that the decrease of the critical current is directly proportional to the reciprocal of square of the buckling wavelength. Change of micro-buckling wavelength with material parameters is discussed. A critical strain in the wire with a filament bridge is analyzed using the finite element method.
